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Submission #1049668

# Submission time Handle Problem Language Result Execution time Memory
1049668 2024-08-09T03:45:42 Z shiomusubi496 Joker (BOI20_joker) C++17
25 / 100
 142 ms 21672 KB 
#include <bits/stdc++.h>

#define rep(i, n) for (int i = 0; i < (int)(n); ++i)
#define rep2(i, a, b) for (int i = (int)(a); i < (int)(b); ++i)
#define rrep(i, n) for (int i = (int)(n) - 1; i >= 0; --i)
#define rrep2(i, a, b) for (int i = (int)(b) - 1; i >= (int)(a); --i)
#define all(v) begin(v), end(v)
#define rall(v) rbegin(v), rend(v)

using namespace std;

using ll = long long;

template<class T, class U> bool chmin(T& a, const U& b) { return a > b ? a = b, true : false; }
template<class T, class U> bool chmax(T& a, const U& b) { return a < b ? a = b, true : false; }

class UndoableUF {
    int n;
    bool flag = true;
    vector<int> par;
    vector<tuple<int, int, bool>> history;

public:
    UndoableUF(int n_) : n(n_ / 2), par(n_, -1) {}
    int find(int x) { return par[x] < 0 ? x : find(par[x]); }
    bool merge(int x, int y) {
        x = find(x), y = find(y);
        history.emplace_back(x, par[x], flag);
        history.emplace_back(y, par[y], flag);
        if (x == y) return false;
        if (par[x] > par[y]) swap(x, y);
        par[x] += par[y];
        par[y] = x;
        if (same(x, (x + n) % (2 * n))) flag = false;
        return true;
    }
    bool same(int x, int y) { return find(x) == find(y); }
    void undo() {
        auto [x, px, _] = history.back(); history.pop_back();
        auto [y, py, f] = history.back(); history.pop_back();
        par[x] = px;
        par[y] = py;
        flag = f;
    }
    void snapshot() { history.clear(); }
    void rollback() {
        while (!history.empty()) undo();
    }
    bool is_bip() { return flag; }
};

int main() {
    int N, M, Q; cin >> N >> M >> Q;
    vector<pair<int, int>> A(M);
    rep (i, M) {
        cin >> A[i].first >> A[i].second;
        --A[i].first, --A[i].second;
    }
    vector<array<int, 3>> B(Q);
    rep (i, Q) {
        cin >> B[i][0] >> B[i][1];
        --B[i][0];
        B[i][2] = i;
    }
    int block = N / sqrt(Q);
    sort(all(B), [&](auto a, auto b) {
        if (a[0] / block != b[0] / block) return a[0] < b[0];
        return a[1] > b[1];
    });
    vector<bool> ans(Q);
    int curl = block, curr = M;
    UndoableUF uf(2 * N);
    for (auto [l, r, k] : B) {
        while (curl <= l) {
            uf.rollback();
            rep2 (i, curl - block, curl) {
                if (i >= M) break;
                uf.merge(A[i].first, A[i].second + N);
                uf.merge(A[i].first + N, A[i].second);
            }
            uf.snapshot();
            curl += block;
            curr = M;
        }
        assert(curr >= r);
        rrep2 (i, r, curr) {
            uf.merge(A[i].first, A[i].second + N);
            uf.merge(A[i].first + N, A[i].second);
        }
        curr = r;
        rep2 (i, curl - block, l) {
            uf.merge(A[i].first, A[i].second + N);
            uf.merge(A[i].first + N, A[i].second);
        }
        ans[k] = uf.is_bip();
        rep2 (i, curl - block, l) uf.undo(), uf.undo();
    }
    rep (i, Q) puts(ans[i] ? "NO" : "YES");
}

Subtask #1
0 / 6.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Runtime error 0 ms 348 KB Execution killed with signal 8
7 Halted 0 ms 0 KB -

Subtask #2
0 / 8.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Runtime error 0 ms 348 KB Execution killed with signal 8
7 Halted 0 ms 0 KB -

Subtask #3
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 123 ms 20292 KB Output is correct
4 Correct 123 ms 21232 KB Output is correct
5 Correct 128 ms 21656 KB Output is correct
6 Correct 127 ms 20416 KB Output is correct
7 Correct 126 ms 19944 KB Output is correct
8 Correct 142 ms 20000 KB Output is correct
9 Correct 114 ms 19900 KB Output is correct
10 Correct 127 ms 20412 KB Output is correct
11 Correct 127 ms 20416 KB Output is correct
12 Correct 126 ms 21672 KB Output is correct
13 Correct 120 ms 20608 KB Output is correct
14 Correct 125 ms 21180 KB Output is correct
15 Correct 129 ms 20928 KB Output is correct
16 Correct 126 ms 20668 KB Output is correct

Subtask #4
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Runtime error 0 ms 348 KB Execution killed with signal 8
7 Halted 0 ms 0 KB -

Subtask #5
0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Runtime error 0 ms 348 KB Execution killed with signal 8
7 Halted 0 ms 0 KB -

Subtask #6
0 / 29.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 348 KB Output is correct
2 Correct 0 ms 348 KB Output is correct
3 Correct 0 ms 348 KB Output is correct
4 Correct 0 ms 348 KB Output is correct
5 Correct 0 ms 348 KB Output is correct
6 Runtime error 0 ms 348 KB Execution killed with signal 8
7 Halted 0 ms 0 KB -